Speaking JavaScript

[EmilyMB]

Discuss Speaking JavaScript, especially following chapters here:

• Chapter 3: The Nature of JavaScript
• Chapter 15: Functions
• Chapter 16: Variables: Scopes, Environments, and Closures
• Chapter 17: Objects and Inheritance

[EmilyMB]

I'm finding Chapter 15 hard to digest...anyone else running into that issue? After a while all the terms seems to coalesce into a mush heap of gobbledy goop.

[nathanows]

Chapter 3:

• The silent failing seems... annoying (I'm sure that's improving, but still)
• Ugh, JS floating point numbers... not fun

Chapter 15:

• The named function thing is kind of cool from a recursion perspective (and what isn't from that perspective?)
• Function hoisting seems convenient but possibly confusing in that you'll have to trace back where a function was defined.
• I'm not sure I completely understand the differences between a function declaration and assigning an anonymous function to a variable, and when you should use one or the other.
• I don't think i realized map was a JS thing as well... nice
• JS named parameters a syntactically annoying...

Chapter 16:

• The scope leak in something like condition stmts seems potentially really annoying, and the IIFE workaround seems pretty hacky
• In JS i've written in the past, I've found global variables really hard not to use... the recommended use of IIFE makes sense, but seems cumbersome
• I've found this article helpful for understanding closures: http://javascriptissexy.com/understand-javascript-closures-with-ease/

Chapter 17 (aka, var couldThisChapterBeLonger = false;)

• I complained on the thoughtbot style guide about them recommending a trailing comma on the last item in a list, the description here might have changed my mind.... "A trailing comma is useful, because you can rearrange properties without having to worry which property is last."

[Jwan622]

I don't get prototypes. Why is this:

function Person(name) { this.name = name; } The object in Person.prototype becomes the prototype of all instances of Person. It contributes part 2: Person.prototype.describe = function () { return 'Person named '+this.name; }; Let’s create and use an instance of Person:

var jane = new Person('Jane'); jane.describe() 'Person named Jane'

Specifically, I don't get this line:

The object in Person.prototype becomes the prototype of all instances of Person.

[bmrsny]

I think prototypes are sticking in a little more. I was confused on when to use a constructor verse a prototype. So I think the problem with Constructors is that when using a constructor like var person1 = New Person, it creates the methods for each object. Versus using a prototype which will use the same methods for all objects, better on performance or memory possibly too.